i saw 6' dob and i was like
dats a big telescope haha... but if your talking about a 6", they are a great beginner aperture that would give you years of awesome views. You should be able to see Orion nebula, Eta Car, 47 tuc, omega cen and much much more DSOs, even faint galaxies in a dark sight. you can also see nebulas as a cloudy patch, i dont think i ever saw a nebula that looked like a star
even through binos or the finder, they are faint and cloudy.
just my 2 c worth
cheers
tony